Network Stumbler is a handy little prog that will find unsecured and secured WiFi Networks.
NetStumbler is a tool for Windows that allows you to detect Wireless Local Area Networks (WLANs) using 802.11b, 802.11a and 802.11g.
and if its unsecured then you can get free internet access.
its ok if the wifi is not secure but with my wifi antenna i pick up networks in my area any so dont see how this helps when your wifi will pick up these networks when in range anyway